UBVI and H alpha photometry of the h and chi Persei cluster

UBVI and H alpha photometry is presented for 17319 stars in vicinity of the young double cluster h and chi Persei. Our photometry extends over a 37' x 1 degrees field centered on the association. We construct reddening contou rs within the imaged field. We find that the two clusters share a common di stance modulus of 11.75 +/- 0.05 and ages of log age(yr) = 7.1 +/- 0.1. Fro m the V-H alpha color, a measure of the H alpha emission strength, we condu ct a survey for emission line objects within the association. We detect a s ample of 33 Be stars, eight of which are new detections. We present a scena rio of evolutionary enhancement of the Be phenomenon to account for the pea k in Be fraction toward the top of the main sequence in the population of h and chi Persei and similar young clusters.